It's hard to go back to old games when newer games have done the same mechanics better. Like the Tomb Raider games - I'd much rather play Uncharted.
The old games I still play are ones that were never really topped. No one has done turn based as well as XCOM and JA2, so I still play those (but JA2 did everything JA1 did, only better, so JA1 is mostly dead to me.) I played Civ1 until Civ4 because I thought it was better than 2 and 3, but could never go back. If I had a working joystick I'd probably play Red Baron or Aces Over from time to time.
I am now slightly concerned that new XCOM may ruin old XCOM for me.